US20130128492A1 - Lighting device - Google Patents
Lighting device Download PDFInfo
- Publication number
- US20130128492A1 US20130128492A1 US13/640,757 US201113640757A US2013128492A1 US 20130128492 A1 US20130128492 A1 US 20130128492A1 US 201113640757 A US201113640757 A US 201113640757A US 2013128492 A1 US2013128492 A1 US 2013128492A1
- Authority
- US
- United States
- Prior art keywords
- light
- scattering element
- lighting device
- light scattering
- coherent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- F21V9/16—
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
- F21V9/00—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters
- F21V9/30—Elements containing photoluminescent material distinct from or spaced from the light source
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21K—NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
- F21K9/00—Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
- F21K9/60—Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction
- F21K9/64—Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
- F21V13/00—Producing particular characteristics or distribution of the light emitted by means of a combination of elements specified in two or more of main groups F21V1/00 - F21V11/00
- F21V13/12—Combinations of only three kinds of elements
- F21V13/14—Combinations of only three kinds of elements the elements being filters or photoluminescent elements, reflectors and refractors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21K—NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
- F21K9/00—Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
- F21K9/20—Light sources comprising attachment means
- F21K9/23—Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings
- F21K9/232—Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
- F21Y2115/00—Light-generating elements of semiconductor light sources
- F21Y2115/10—Light-emitting diodes [LED]
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
- F21Y2115/00—Light-generating elements of semiconductor light sources
- F21Y2115/30—Semiconductor lasers
Definitions
- the present inventive concept generally relates to lighting, and more particularly to a lighting device and a corresponding lamp utilizing a light source and a light scattering element comprising luminescent material to produce light.
- Luminescent materials such as phosphors, are materials that emit light (infrared to ultraviolet) under external energy excitation.
- the incident energy in the form of high energy electron, photons, or electric field, can then be re-emitted in the form of electromagnetic radiation.
- Incident energy in the form of radiation within a first range of wavelengths of the electromagnetic spectra is reemitted within a second range of wavelengths of the electromagnetic spectra by the luminescent material.
- At least the second range of wavelengths is selected within the visible range of the electromagnetic spectra.
- violet and blue light is utilized to excite the luminescent material. This is shown in U.S. 2009/0176430 A1, which discloses a method of making a white light source by means of arranging a suitable amount of phosphor material on a violet LED, which phosphor material is arranged to emit yellow light subsequently to absorbing violet light. Further, the yellow light is mixed with the violet light, such that a viewer perceives the mixture of blue and yellow light as a white light with a high color rendering index.
- a lighting device comprising a light source for providing light, and a light scattering element arranged for receiving light from the light source.
- the light scattering element comprises luminescent material adapted for converting part of the provided light into a different wavelength.
- the light scattering element is arranged to transmit and scatter part of the provided light without conversion.
- the light source is a laser arranged to provide high brightness coherent light, such that upon receiving the coherent light, light being outputted from the light scattering element comprises high brightness incoherent light originating from converted light providing a sparkle lighting effect, and coherent light providing a speckle effect.
- a lighting device which outputs light for illumination having a dual lighting effect.
- a coherent light source such as a laser
- a concentrated light input and thereby high brightness pump radiation
- the light scattering element which then outputs very bright sparkling light originating from the high brightness laser light being converted by the luminescent material and reemitted in all directions.
- the size of the light distributions incident to and emitted from the light scattering element determines the brightness of the outputted light, and consequently the amount of high brightness (sparkling) in the outputted light.
- the light scattering element may be beneficial to use a very small light scattering element which still is very bright and sparkling, but in many cases the light scattering element itself may be relatively big (for reasons of easy handling in manufacturing and of heatsinking), and still prodvide very bright and sparkling light.
- the outputted light is further characterized in spikes of light beams leaving the scattering element light originating from a speckle lighting effect.
- a part of the laser light is outputted from the light scattering element without being converted, thus retaining its coherent properties and thereby providing the speckle lighting effect due to interference between coherent light traveling with different light paths.
- coherence may also refer to temporal coherence, which is related to the spectral width of the laser. When the spectral width is narrow, which is a typical characteristics of a laser, speckle patterns are generated due to interference phenomena.
- Providing a sparkle lighting effect and speckle lighting effect is applicable to enhance the lighting effect of candle lamp devices in chandeliers or other types of ambiance light.
- the speckle creates a new ambiance effect projected on a surface (wall, ceiling) and allows designers to create new atmosphere in a room.
- the degree of transmitted coherent light is controlled by arranging the light scattering element to have at least one of a predetermined degree of light scattering, a predetermined dopant concentration in the luminescent material, and a predetermined thickness of the light scattering device.
- the light source and the light scattering element are separated a predetermined distance from each other, which is advantageous when a high power light source is utilized to provide a high brightness of the outputted light from the lighting device.
- the light source and the light scattering element may be arranged with separate cooling by means of e.g. an active or passive heat sink.
- the light source i.e. the laser
- light scattering element e.g. a phosphor tile
- this gives an impression of a floating light output from the lighting device as compared to a LED-source where the phosphor tile is stacked directly on the LED.
- a laser as a light source its light output can be efficiently collected and focused on to the light-scattering element.
- a remote distance between the laser source and phosphor material can be enlarged which provides design freedom.
- the design freedom has a feature that the light-scattering element, when placed at a distance, can be viewed from many directions, having the advantages that (a) a larger fraction of the emitted light is effectively used, and that (b) the lamp will have a “distinctive look”.
- the lighting device further comprises a lens arranged between the light source and the light scattering element.
- the coherent light beam from the light source is advantageously controlled by means of the lens, which is arranged in the light beam path. Focusing the light beam onto the light scattering element is advantageous for some embodiments of the lighting device, since this provides that all the light energy enters the light scattering element within a predetermined area, thereby providing a very bright spot.
- the lens may alternatively be used to defocus the light beam such that a desired beam area with a desirable light intensity of the provided light is selected.
- control of the light beam by means of the lens is advantageous in other embodiments of the lighting device, in which the shape of the light scattering element may be selected such that a coherent light beam having a certain size of the spot area is desirable.
- the brightness of the outputted light is controlled by means of the lens by focusing or determining the degree of defocus of the light entering the light scattering element.
- Focusing/defocusing of the laser beam mainly determines the brightness (cd/m 2 ) of the light distribution in the light scattering element.
- the light source e.g.
- the laser may be kept at a constant power level, providing the same amount of coherent light, while the lens is utilized to control the brightness of the light outputted from the lighting device.
- the luminescent material is a phosphor.
- the phosphor is excitable in the UV-blue-green region within a range of wavelengths from 380 to 520 nm.
- the light scattering element is a ceramic plate comprising at least one of YAG:Ce, LuAG:Ce, SSONe, and eCAS phosphor powder.
- the ceramic plate is polycrystalline and the degree of scattering of the ceramic plate is selected by applying predetermined sintering conditions during manufacturing.
- the ceramic plate is a Lumiramic tile.
- the Lumiramic tile i.e. sintered phosphor
- the high brightnesses generated in the light scattering element requires good cooling which may be obtained e.g, by proper mounting on to a metal or ceramic heat sink.
- the light scattering element is U-shaped or tubular, or shaped like one of a plate, a cube, and a rectangular solid.
- the light source provides blue, ultraviolet light, or green light.
- a lamp comprising a lighting device according to the present inventive concept, a socket for providing power to the light source, a heat sink onto which the light scattering element is mounted, and a lamp bulb being engaged with the socket and encompassing the lighting device.
- the lamp socket may further be retrofitted such that the lamp can replace incandescent light bulbs in existing luminaires.
- the lamp further comprises shielding for spatially limiting the distribution of light from the lamp.
- the lamp further comprises reflecting elements.
- FIG. 1 is a schematic illustrative side view of an embodiment of a lighting device according to the present inventive concept.
- FIG. 2 is a schematic illustrative side view of an embodiment of a lighting device according to the present inventive concept.
- FIGS. 3 a 3 c are exemplifying illustrations of the intensity distribution in the forward direction from an embodiment of a lighting device according to the present inventive concept as a function of different defocusing of the light beam entering the light scattering element.
- FIGS. 4 a and 4 b are partly cut-open side views of embodiments of a lamp according to the present inventive concept.
- FIGS. 5 a - 5 d are schematic cross-sectional side views of different shapes of the light scattering element in embodiments of a lighting device according to the present inventive concept.
- a coherent light source 1 such as a blue laser
- a light scattering element 2 such as a phosphor coated transparent substrate
- the transparent substrate may be a slab of glass, plastic, or a ceramic.
- the phosphor material may be embedded, or dispersed, within the transparent substrate.
- the phosphor material of the light scattering element 2 is selected so as to convert light from the light source from the initial wavelength(s) to light of longer wave length(s).
- the phosphor material absorbs at least part of the light provided from the lights source, and subsequently emits light within a longer and preferably visible range of wavelengths.
- the outputted wavelength(s) is here depending on which identity and amount of phosphor material is utilized, and further on the composition of the phosphor material.
- the phosphor material may include only a single phosphor, or compositions of two or more phosphors to obtain a desired color of the outputted light.
- Light which is emitted by the light source 1 is illustrated by light beam I L , in the figures.
- the light source is assumed to emit a single UV-blue wavelength ⁇ L .
- the light divergence of the laser beam is elliptic 5/25 deg full angle (depending on type of laser). Due to this divergence the coherent beam spot becomes larger if the distance of the light scattering element 2 to the laser source 1 is selected to be a longer distance. With that larger spot of the incident light beam (mm 2 ) the brightness (cd/mm 2 ) becomes less.
- the light beam I L impinges on the light scattering element 2 , and part of the received light is converted to a longer wavelength ⁇ P by the phosphor material providing a sparkle lighting effect from the luminescent material.
- the converted light is emitted in all directions, and is illustrated by the dashed arrows in FIG. 1 .
- some of the light beam I L is scattered in all directions as blue light of wavelength ⁇ L , as is illustrated by solid arrows in FIG. 1 .
- the scattered light is mixed and when selecting the phosphor such that ⁇ P is yellow, the proper combination of yellow and blue light is perceived as white light to a viewer.
- the light scattering element 2 is arranged such that part of the incoming light beam I L , i.e.
- speckle is transmitted through the light scattering element 2 , and keeps its coherent properties, such that at a surface e.g. on a screen 100 which is illuminated with the light outputted in the forward direction, a speckle pattern is visible.
- Speckle is exhibited by a coherent imaging modality and results from the coherent addition of multiple light waves of different phases.
- the appearance of the speckle pattern is granular or mottled appearance.
- the speckle pattern is a result from low scattering of multiple waves in the forward direction from within the volume (and/or surfaces) of the light scattering element 2 .
- the speckle pattern provides a speckle lighting effect to the light outputted from the lighting device 10 , increasing the viewing experience for the viewer.
- the speckle lighting effect may be achieved also in other directions since the light scattering element may scatter coherent light in all direction.
- the speckle lighting effect occurs as spikes (vs. angle) in the emitted light distributions.
- the speckle lighting effect may arise due to the narrow spectral width of the laser light source.
- phosphor material excitable in the UV-blue-green region within a range of wavelengths from 380 to 520 nm is applicable.
- the phosphor coated or phosphor dispersed transparent substrate can be replaced with a transparent or translucent luminescent ceramic, particularly a so-called Lumiramic tile.
- Lumiramic tiles are ceramic phosphor converter plates which convert the blue light of a blue LED into another color, e.g. yellow or red.
- a Lumiramic tile is manufactured by sintering high-purity phosphor powders into a solid ceramic. During this process the color point and lumen output of the Lumiramic tile are fixed. The sintering process may be very accurately controlled, such that fine-tuning of the concentration of ions that convert the light, e.g.
- the luminescent ceramic behaves as tightly packed individual phosphor particles providing scattering of the light through small optical discontinuities at the interface of different phosphor particles.
- a Lumiramic tile as the light scattering element is preferred because of its high thermal conductivity.
- the high brightnesses generated in the light scattering element 2 require good cooling, i.e. proper mounting on to a metal or ceramic heat sink and the mentioned good thermal conductivity.
- the thickness of the Lumiramic tile will determined the amount of light that is transmitted, absorbed and emitted through photoluminescence in the tile, and the amount of light that is scattered within the tile.
- the selection of the degree of brightness, i.e sparkling lighting effect, vs speckle lighting effect to achieve from the light scattering element must be selected in accordance with the desired application area of the lamp. Further, a low brightness will not produce a strong sparkle lighting effect, but a too high brightness can be irritating when viewed from a short distance.
- Lumiramics tiles that are applicable to the present inventive concept are tiles comprising Cerium-doped Yttrium aluminium garnet, YAG:Ce (yellow/white), Cerium-doped Lutetium Aluminum Garnet, LuAG:Ce (green/yellow/white), Sr 0.98 Si 2 O 2 N 2 IEu 0.02 , SSONe (green), or eCAS (red).
- the light source of the light emitting device may in principle be realized by any suitable technology for providing coherent light. It is preferably a coherent UV, blue, or green light source.
- the property of a laser in respect to the brightness (cd/m 2 ) is that the light of a laser is concentrated in a very small surface, and has an about 100 times higher brightness with respect to power output, than a Laser LED with the same power output. With this high brightness, the outputted light of a Lumiramic is sparkling.
- a light source such as a semiconductor laser (e.g. a side-emitting laser or VCSEL) generally produce a divergent output beam.
- a lens can be used to convert the divergent beam into a parallel or convergent beam.
- the lens design e.g. focal distance f and aberrations
- the size and shape of the (coherent light) light distribution incident at the light scattering element can be controlled, e.g. be varied from very bright and concentrated to more extended and less bright (in terms of W/m 2 incident to, or measured as brightness cd/m 2 emitted from the light scattering element).
- the brightness of the luminescence from the light scattering element i.e.
- the incoherent light will also increase or decrease when the brightness of the incident light increases or decreases, respectively.
- the resulting brightnesses of the backward and forward emitted luminescence and pump radiation are not only determined by the lens design and position but also by the thickness, scattering, and doping concentrations of the Lumiramic/phosphor used as the light scattering element. As illustrated in FIG.
- an embodiment of the lighting device 20 in addition to the light source 1 , which here is a blue laser, wavelength 445 nm light, and the light scattering element 2 , a 1 mm 2 ⁇ 120 ⁇ m YAG:Ce Lumiramic tile designed for wavelength converting coherent blue light, further comprises a lens 4 , such as a AC-296 (f 3 mm) by Philips Optics (now Anteryon).
- the lens 4 is arranged to shape the beam and focus it on the light scattering element 2 .
- FIG. 2 a screen 100 is arranged 2 m from the lighting device 20 and the lens 4 is arranged a distance equal to its focal length minus the thickness of the light scattering element 2 , i.e. the light beam is slightly defocused with respect to the light scattering element. By repositioning of the lens 4 , different degrees of defocusing of the light beam is allowed.
- FIG. 3 a illustrates the resulting light distribution as the outputted light from the lighting device 20 is projected onto the screen 100 , when arranging the lens 4 as to focus the laser beam I L onto the light scattering element 2 , defocus of the laser beam is 0.
- FIGS. 3 a - 3 c By choosing the lens design and distance to the light source and light scattering element not only the brightnesses, but also the characteristics of the (transmitted and reflected) speckle patterns are influenced. This is illustrated in FIGS. 3 a - 3 c .
- the lens design and its position with respect to the light source and the Lumiramic/phosphor are chosen to produce a high brightness, the speckle patterns are relatively coarse ( FIG. 3 a ). But when a lower brightness is produced the speckle patterns are relatively fine ( FIG. 3 c ).
- the lens is arranged such that the laser beam I L is defocused 5 mm from the light scattering element 2 , wherein the laser light energy per input area is decreased and the produced speckle pattern on the screen is more fine than FIG. 3 a .
- FIG. 3 c illustrates how an even finer speckle pattern is achieved when defocusing the light beam I L 50 mm. This effect is caused by the diffraction of the beam in the light scattering element.
- a viewer viewing the outputted light in an angle ⁇ will with the present inventive concept experiencing varying colour of the outputted light under different viewing angles.
- Light spread backwards from the light scattering element 2 , with respect to the traveling direction of the light beam is typically the resulting light of light originating from scattering of the laser light and converted light, i.e. white light when the laser light is blue and the converted light is yellow, while light in the forward direction, depending on the degree of transmitted coherent light, is blue.
- Lumiramic more or less coherent light is scattered in the Lumiramic. Lumiramics with low scattering behavior passes through more coherent blue light which is viewed in the forward direction.
- a lighting device is arranged in a lamp 30 .
- a light source 1 such as a ⁇ L 445 nm laser is fixed in an aluminum housing which acts as a heatsink for the laser.
- the lamp 30 comprises a socket 16 for connecting the lamp 30 to the main voltage of the electricity net.
- the lamp further comprises a driver (not shown) for converting the main voltage to a voltage and current suitable for the light source 1 , such that the light source 1 is provided with electrical power when the lamp 30 is activated.
- an AC296 focus lens 4 is placed in front of the laser 1 and a Lumiramic tile 2 is positioned in an ⁇ 10 mm Cu fixture plate acting as a heat sink 15 .
- the heat sink 15 is of 0.5 mm thickness and is arranged at a distance of 25 mm in front of the lens 4 .
- the lens 4 is arranged to focus the light beam generated by the laser 1 onto the Lumiramic tile 2 .
- the heat sink 15 has a ⁇ 0.5 mm diaphragm hole to pass the laser beam provided by the laser 1 .
- a glass bulb 19 encompasses the arrangement described above, and is of a CFL candle lamp, even as the socket 16 which is a E14 fitting.
- the light scattering element 2 is arranged on the heat sink 15 , such that heat, which is created as the laser light impinges the light scattering element 2 , can be dissipated.
- the heat sink 15 is arranged on a support 14 , which further is arranged to position the light scattering element a predetermined distance from the light source 1 and the lens 4 .
- the light scattering element 2 and the laser 1 are separated such that light being outputted from the light scattering element may be scattered and emitted backwards towards the laser 1 .
- Reflecting elements 17 are arranged to direct backscattered light in the forward direction thus increasing the amount of light in the forward direction.
- the shielding can be arranged to shield off light outputted from the lighting device in any desirable direction limiting the distribution of light from the lamp depending on the specific application.
- the light scattering element 2 is a Lumiramic YAG:Ce.
- concentration of the active dopant (Ce in the case of YAG:Ce)
- degree of scattering which is determined by the sintering conditions
- thickness of the Lumiramic tile is utilized to control the degree of scattered light, converted light, and transmitted light being outputted from the lamp.
- part of the blue laser beam is transmitted through the light scattering element 2 .
- a high degree of transmitted coherent light is achievable with a low scattering degree, a low dopant degree, and/or a low thickness of the light scattering element, or a combination of the three.
- the light scattering element 2 may be arranged having a high degree of scattering which results in less transmitted coherent light and a more homogenous yellow, or white appearance of the light also in the forward directions.
- the lower degree of transmitted coherent light is an effect of high scattering degree, a high dopant concentration, and/or a high thickness, or a combination of the three.
- FIGS. 5 a - 5 d are schematic cross-sectional side views of different shapes of the light scattering element in embodiments of a lighting device according to the present inventive concept. These shapes provide a secondary point of entrance for the backscattered light beam.
- Part of the coherent light beam is absorbed in the Lumiramic tile, while part of the coherent light beam passes the Lumiramic tile. Further, a part of the coherent light beam is reflected by the Lumiramic tile back to where it came from, only over a 180 ′angle (back scattering). The back scattered coherent light can be used again to enforce the luminescent light spot (sparkle spot).
- Using a U-shape cube FIG. 5 c ) firstly light is focused on the top Lumiramic tile where primarily the coherent light beam is absorbed by the Lumiramic tile.
- the back scattered coherent light meets the vertical walls of the U-shape cube, where the coherent light beam can make a second entry of a Lumiramic tile to convert into the desired wavelength.
- FIG. 5 b and FIG. 5 d Other shapes with the same purpose are applicable ( FIG. 5 b and FIG. 5 d ).
- the tubular/cylindrical shape ( FIG. 5 d ) can provide a more filament like shape known from an incandescent lamp.
- the tubular shape creates more design freedom.
- the geometry of the light scattering element which has been exemplified above, with reference to FIGS. 5 a - 5 d, can be chosen to select the luminance (cd/m 2 ) visible to the eye, and the preferably to avoid a too high luminance, which is perceived as “glare” rather than sparkle, the latter which is one of the objects to achieve with the present inventive concept.
- the sparkle lighting effect desirable for use in lighting devices or candle lamps in applications like chandeliers.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Optics & Photonics (AREA)
- Non-Portable Lighting Devices Or Systems Thereof (AREA)
- Luminescent Compositions (AREA)
- Arrangement Of Elements, Cooling, Sealing, Or The Like Of Lighting Devices (AREA)
- Semiconductor Lasers (AREA)
Abstract
Description
- The present inventive concept generally relates to lighting, and more particularly to a lighting device and a corresponding lamp utilizing a light source and a light scattering element comprising luminescent material to produce light.
- In recent years the development of alternative lighting devices to replace traditional incandescent lamps in different lighting applications have resulted in a number of solutions which provide white light by utilizing light emitting diodes, LEDs, in combination with luminescent materials. Luminescent materials, such as phosphors, are materials that emit light (infrared to ultraviolet) under external energy excitation. The incident energy, in the form of high energy electron, photons, or electric field, can then be re-emitted in the form of electromagnetic radiation. Incident energy in the form of radiation within a first range of wavelengths of the electromagnetic spectra is reemitted within a second range of wavelengths of the electromagnetic spectra by the luminescent material. For lighting purposes, at least the second range of wavelengths is selected within the visible range of the electromagnetic spectra. Further, in known lighting devices, to provide a high efficiency of light energy conversion, violet and blue light is utilized to excite the luminescent material. This is shown in U.S. 2009/0176430 A1, which discloses a method of making a white light source by means of arranging a suitable amount of phosphor material on a violet LED, which phosphor material is arranged to emit yellow light subsequently to absorbing violet light. Further, the yellow light is mixed with the violet light, such that a viewer perceives the mixture of blue and yellow light as a white light with a high color rendering index.
- It is an object of the present invention to provide an alternative and improved lighting device and lamp with alternative lighting effects.
- According to a first aspect of the invention, this and other objects are achieved with a lighting device comprising a light source for providing light, and a light scattering element arranged for receiving light from the light source. The light scattering element comprises luminescent material adapted for converting part of the provided light into a different wavelength. The light scattering element is arranged to transmit and scatter part of the provided light without conversion. The light source is a laser arranged to provide high brightness coherent light, such that upon receiving the coherent light, light being outputted from the light scattering element comprises high brightness incoherent light originating from converted light providing a sparkle lighting effect, and coherent light providing a speckle effect.
- Thereby a lighting device is provided which outputs light for illumination having a dual lighting effect. By utilizing a coherent light source such as a laser, a concentrated light input, and thereby high brightness pump radiation, is provided to the light scattering element which then outputs very bright sparkling light originating from the high brightness laser light being converted by the luminescent material and reemitted in all directions. The size of the light distributions incident to and emitted from the light scattering element determines the brightness of the outputted light, and consequently the amount of high brightness (sparkling) in the outputted light. Depending on the characteristics of the light scattering element it may be beneficial to use a very small light scattering element which still is very bright and sparkling, but in many cases the light scattering element itself may be relatively big (for reasons of easy handling in manufacturing and of heatsinking), and still prodvide very bright and sparkling light.
- The outputted light is further characterized in spikes of light beams leaving the scattering element light originating from a speckle lighting effect. A part of the laser light is outputted from the light scattering element without being converted, thus retaining its coherent properties and thereby providing the speckle lighting effect due to interference between coherent light traveling with different light paths. Here, coherence may also refer to temporal coherence, which is related to the spectral width of the laser. When the spectral width is narrow, which is a typical characteristics of a laser, speckle patterns are generated due to interference phenomena.
- Providing a sparkle lighting effect and speckle lighting effect is applicable to enhance the lighting effect of candle lamp devices in chandeliers or other types of ambiance light. The speckle creates a new ambiance effect projected on a surface (wall, ceiling) and allows designers to create new atmosphere in a room.
- According to an embodiment of the lighting device, the degree of transmitted coherent light is controlled by arranging the light scattering element to have at least one of a predetermined degree of light scattering, a predetermined dopant concentration in the luminescent material, and a predetermined thickness of the light scattering device.
- Thereby, a range of lighting effects varying from high sparkle lighting effect with low speckle lighting effect, to low sparkle lighting effect (brightness) with high speckle lighting effect of the lighting device is obtainable. This control over the light emission of the lighting device allows a great freedom of design and setting of ambiance light.
- According to an embodiment of the lighting device, the light source and the light scattering element are separated a predetermined distance from each other, which is advantageous when a high power light source is utilized to provide a high brightness of the outputted light from the lighting device. The light source and the light scattering element may be arranged with separate cooling by means of e.g. an active or passive heat sink.
- Further, when the light source, i.e. the laser, and light scattering element, e.g. a phosphor tile, are separated (remote), this gives an impression of a floating light output from the lighting device as compared to a LED-source where the phosphor tile is stacked directly on the LED. Using a laser as a light source its light output can be efficiently collected and focused on to the light-scattering element. A remote distance between the laser source and phosphor material can be enlarged which provides design freedom. The design freedom has a feature that the light-scattering element, when placed at a distance, can be viewed from many directions, having the advantages that (a) a larger fraction of the emitted light is effectively used, and that (b) the lamp will have a “distinctive look”.
- According to an embodiment of the lighting device, the lighting device further comprises a lens arranged between the light source and the light scattering element. Thus, the coherent light beam from the light source is advantageously controlled by means of the lens, which is arranged in the light beam path. Focusing the light beam onto the light scattering element is advantageous for some embodiments of the lighting device, since this provides that all the light energy enters the light scattering element within a predetermined area, thereby providing a very bright spot. Further, the lens may alternatively be used to defocus the light beam such that a desired beam area with a desirable light intensity of the provided light is selected.
- Further, the control of the light beam by means of the lens is advantageous in other embodiments of the lighting device, in which the shape of the light scattering element may be selected such that a coherent light beam having a certain size of the spot area is desirable.
- According to an embodiment of the lighting device, the brightness of the outputted light is controlled by means of the lens by focusing or determining the degree of defocus of the light entering the light scattering element.
- Focusing/defocusing of the laser beam, mainly determines the brightness (cd/m2) of the light distribution in the light scattering element. Thereby, the light source, e.g.
- the laser, may be kept at a constant power level, providing the same amount of coherent light, while the lens is utilized to control the brightness of the light outputted from the lighting device.
- According to an embodiment of the lighting device, the luminescent material is a phosphor.
- According to an embodiment of the lighting device, the phosphor is excitable in the UV-blue-green region within a range of wavelengths from 380 to 520 nm.
- According to an embodiment of the lighting device, the light scattering element is a ceramic plate comprising at least one of YAG:Ce, LuAG:Ce, SSONe, and eCAS phosphor powder.
- According to an embodiment of the lighting device, the ceramic plate is polycrystalline and the degree of scattering of the ceramic plate is selected by applying predetermined sintering conditions during manufacturing.
- According to an embodiment of the lighting device, the ceramic plate is a Lumiramic tile. The Lumiramic tile (i.e. sintered phosphor) is advantangeous because of its high thermal conductivity. The high brightnesses generated in the light scattering element requires good cooling which may be obtained e.g, by proper mounting on to a metal or ceramic heat sink.
- According to an embodiment of the lighting device, the light scattering element is U-shaped or tubular, or shaped like one of a plate, a cube, and a rectangular solid.
- According to an embodiment of the lighting device, the light source provides blue, ultraviolet light, or green light.
- According to a second aspect of the invention, there is provided a lamp comprising a lighting device according to the present inventive concept, a socket for providing power to the light source, a heat sink onto which the light scattering element is mounted, and a lamp bulb being engaged with the socket and encompassing the lighting device. The lamp socket may further be retrofitted such that the lamp can replace incandescent light bulbs in existing luminaires.
- According to an embodiment of the lamp, the lamp further comprises shielding for spatially limiting the distribution of light from the lamp.
- According to an embodiment of the lamp, the lamp further comprises reflecting elements.
- It is noted that the invention relates to all possible combinations of features recited in the claims.
- This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiment(s) of the invention.
-
FIG. 1 is a schematic illustrative side view of an embodiment of a lighting device according to the present inventive concept. -
FIG. 2 is a schematic illustrative side view of an embodiment of a lighting device according to the present inventive concept. -
FIGS. 3 a 3 c are exemplifying illustrations of the intensity distribution in the forward direction from an embodiment of a lighting device according to the present inventive concept as a function of different defocusing of the light beam entering the light scattering element. -
FIGS. 4 a and 4 b are partly cut-open side views of embodiments of a lamp according to the present inventive concept. -
FIGS. 5 a-5 d are schematic cross-sectional side views of different shapes of the light scattering element in embodiments of a lighting device according to the present inventive concept. - Embodiments of the present inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
- With reference to
FIG. 1 , which is a schematic illustration of an embodiment of alighting device 10 according to the present inventive concept, a coherent light source 1, such as a blue laser, and alight scattering element 2, such as a phosphor coated transparent substrate, are positioned on a suitable support (not shown). The transparent substrate may be a slab of glass, plastic, or a ceramic. Further, the phosphor material may be embedded, or dispersed, within the transparent substrate. The phosphor material of thelight scattering element 2 is selected so as to convert light from the light source from the initial wavelength(s) to light of longer wave length(s). That is the phosphor material absorbs at least part of the light provided from the lights source, and subsequently emits light within a longer and preferably visible range of wavelengths. The outputted wavelength(s) is here depending on which identity and amount of phosphor material is utilized, and further on the composition of the phosphor material. The phosphor material may include only a single phosphor, or compositions of two or more phosphors to obtain a desired color of the outputted light. - Light which is emitted by the light source 1 is illustrated by light beam IL, in the figures. For simplicity, in the following examples the light source is assumed to emit a single UV-blue wavelength λL. The light divergence of the laser beam is elliptic 5/25 deg full angle (depending on type of laser). Due to this divergence the coherent beam spot becomes larger if the distance of the
light scattering element 2 to the laser source 1 is selected to be a longer distance. With that larger spot of the incident light beam (mm2) the brightness (cd/mm2) becomes less. The light beam IL impinges on thelight scattering element 2, and part of the received light is converted to a longer wavelength λP by the phosphor material providing a sparkle lighting effect from the luminescent material. The converted light is emitted in all directions, and is illustrated by the dashed arrows inFIG. 1 . In addition, some of the light beam IL is scattered in all directions as blue light of wavelength λL, as is illustrated by solid arrows inFIG. 1 . The scattered light is mixed and when selecting the phosphor such that λP is yellow, the proper combination of yellow and blue light is perceived as white light to a viewer. Furthermore, thelight scattering element 2 is arranged such that part of the incoming light beam IL, i.e. light of blue wavelength λL, is transmitted through thelight scattering element 2, and keeps its coherent properties, such that at a surface e.g. on ascreen 100 which is illuminated with the light outputted in the forward direction, a speckle pattern is visible. Speckle is exhibited by a coherent imaging modality and results from the coherent addition of multiple light waves of different phases. The appearance of the speckle pattern is granular or mottled appearance. The speckle pattern is a result from low scattering of multiple waves in the forward direction from within the volume (and/or surfaces) of thelight scattering element 2. The speckle pattern provides a speckle lighting effect to the light outputted from thelighting device 10, increasing the viewing experience for the viewer. Further, the speckle lighting effect may be achieved also in other directions since the light scattering element may scatter coherent light in all direction. The speckle lighting effect occurs as spikes (vs. angle) in the emitted light distributions. The speckle lighting effect may arise due to the narrow spectral width of the laser light source. In embodiments of the lighting device, phosphor material excitable in the UV-blue-green region within a range of wavelengths from 380 to 520 nm is applicable. - Further, as will be described herein under, the phosphor coated or phosphor dispersed transparent substrate can be replaced with a transparent or translucent luminescent ceramic, particularly a so-called Lumiramic tile. Lumiramic tiles are ceramic phosphor converter plates which convert the blue light of a blue LED into another color, e.g. yellow or red. A Lumiramic tile is manufactured by sintering high-purity phosphor powders into a solid ceramic. During this process the color point and lumen output of the Lumiramic tile are fixed. The sintering process may be very accurately controlled, such that fine-tuning of the concentration of ions that convert the light, e.g. the degree of dopant in the material, and the scattering of light in the plate is obtainable during the manufacturing process. The luminescent ceramic behaves as tightly packed individual phosphor particles providing scattering of the light through small optical discontinuities at the interface of different phosphor particles. For more information on Lumiramic tiles, see U.S. 2005/0269582 A1.
- Utilizing a Lumiramic tile as the light scattering element is preferred because of its high thermal conductivity. The high brightnesses generated in the
light scattering element 2 require good cooling, i.e. proper mounting on to a metal or ceramic heat sink and the mentioned good thermal conductivity. - Further, the thickness of the Lumiramic tile will determined the amount of light that is transmitted, absorbed and emitted through photoluminescence in the tile, and the amount of light that is scattered within the tile. The selection of the degree of brightness, i.e sparkling lighting effect, vs speckle lighting effect to achieve from the light scattering element must be selected in accordance with the desired application area of the lamp. Further, a low brightness will not produce a strong sparkle lighting effect, but a too high brightness can be irritating when viewed from a short distance.
- Examples of Lumiramics tiles that are applicable to the present inventive concept are tiles comprising Cerium-doped Yttrium aluminium garnet, YAG:Ce (yellow/white), Cerium-doped Lutetium Aluminum Garnet, LuAG:Ce (green/yellow/white), Sr0.98Si2O2N2IEu0.02, SSONe (green), or eCAS (red).
- The light source of the light emitting device may in principle be realized by any suitable technology for providing coherent light. It is preferably a coherent UV, blue, or green light source. The property of a laser in respect to the brightness (cd/m2) is that the light of a laser is concentrated in a very small surface, and has an about 100 times higher brightness with respect to power output, than a Laser LED with the same power output. With this high brightness, the outputted light of a Lumiramic is sparkling.
- A light source such as a semiconductor laser (e.g. a side-emitting laser or VCSEL) generally produce a divergent output beam. A lens can be used to convert the divergent beam into a parallel or convergent beam. By choosing the lens design (e.g. focal distance f and aberrations) and its distance to the light source (laser) and the light scattering element, the size and shape of the (coherent light) light distribution incident at the light scattering element can be controlled, e.g. be varied from very bright and concentrated to more extended and less bright (in terms of W/m2 incident to, or measured as brightness cd/m2 emitted from the light scattering element). The brightness of the luminescence from the light scattering element (i.e. the incoherent light) will also increase or decrease when the brightness of the incident light increases or decreases, respectively. Further, the resulting brightnesses of the backward and forward emitted luminescence and pump radiation are not only determined by the lens design and position but also by the thickness, scattering, and doping concentrations of the Lumiramic/phosphor used as the light scattering element. As illustrated in
FIG. 2 , an embodiment of thelighting device 20 in addition to the light source 1, which here is a blue laser, wavelength 445 nm light, and thelight scattering element 2, a 1 mm2×120 μm YAG:Ce Lumiramic tile designed for wavelength converting coherent blue light, further comprises alens 4, such as a AC-296 (f=3 mm) by Philips Optics (now Anteryon). To control the brightness of the light beam IL as it reaches thelight scattering element 2, thelens 4 is arranged to shape the beam and focus it on thelight scattering element 2. - Focusing, and defocusing, of the light beam IL gives the effect of achieving different speckle patterns for the same
light scattering element 2. InFIG. 2 ascreen 100 is arranged 2 m from thelighting device 20 and thelens 4 is arranged a distance equal to its focal length minus the thickness of thelight scattering element 2, i.e. the light beam is slightly defocused with respect to the light scattering element. By repositioning of thelens 4, different degrees of defocusing of the light beam is allowed.FIG. 3 a illustrates the resulting light distribution as the outputted light from thelighting device 20 is projected onto thescreen 100, when arranging thelens 4 as to focus the laser beam IL onto thelight scattering element 2, defocus of the laser beam is 0. - By choosing the lens design and distance to the light source and light scattering element not only the brightnesses, but also the characteristics of the (transmitted and reflected) speckle patterns are influenced. This is illustrated in
FIGS. 3 a-3 c. When the lens design and its position with respect to the light source and the Lumiramic/phosphor are chosen to produce a high brightness, the speckle patterns are relatively coarse (FIG. 3 a). But when a lower brightness is produced the speckle patterns are relatively fine (FIG. 3 c). InFIG. 3 b) the lens is arranged such that the laser beam IL is defocused 5 mm from thelight scattering element 2, wherein the laser light energy per input area is decreased and the produced speckle pattern on the screen is more fine thanFIG. 3 a. Further,FIG. 3 c) illustrates how an even finer speckle pattern is achieved when defocusing the light beam IL 50 mm. This effect is caused by the diffraction of the beam in the light scattering element. - A viewer viewing the outputted light in an angle θ, will with the present inventive concept experiencing varying colour of the outputted light under different viewing angles. Light spread backwards from the
light scattering element 2, with respect to the traveling direction of the light beam is typically the resulting light of light originating from scattering of the laser light and converted light, i.e. white light when the laser light is blue and the converted light is yellow, while light in the forward direction, depending on the degree of transmitted coherent light, is blue. Depending on the type of Lumiramic more or less coherent light is scattered in the Lumiramic. Lumiramics with low scattering behavior passes through more coherent blue light which is viewed in the forward direction. Depending on the angle of view, the influence of the scattered light beam takes over and a more yellow/white light is experienced. The effect is known as Color over angle. With a high scattering Lumiramic material less coherent blue light passes resulting in a low forward coherent blue light beam. In this case only a yellow/white light beam is viewed. - Referring now to
FIG. 4 a) a lighting device according to the present inventive concept is arranged in alamp 30. A light source 1, such as a λL 445 nm laser is fixed in an aluminum housing which acts as a heatsink for the laser. Thelamp 30 comprises asocket 16 for connecting thelamp 30 to the main voltage of the electricity net. The lamp further comprises a driver (not shown) for converting the main voltage to a voltage and current suitable for the light source 1, such that the light source 1 is provided with electrical power when thelamp 30 is activated. Further, in a distance of proximately 3 mm anAC296 focus lens 4 is placed in front of the laser 1 and aLumiramic tile 2 is positioned in an Ø10 mm Cu fixture plate acting as aheat sink 15. Theheat sink 15 is of 0.5 mm thickness and is arranged at a distance of 25 mm in front of thelens 4. Thelens 4 is arranged to focus the light beam generated by the laser 1 onto theLumiramic tile 2. Theheat sink 15 has a Ø0.5 mm diaphragm hole to pass the laser beam provided by the laser 1. - A
glass bulb 19 encompasses the arrangement described above, and is of a CFL candle lamp, even as thesocket 16 which is a E14 fitting. - The
light scattering element 2 is arranged on theheat sink 15, such that heat, which is created as the laser light impinges thelight scattering element 2, can be dissipated. Theheat sink 15 is arranged on asupport 14, which further is arranged to position the light scattering element a predetermined distance from the light source 1 and thelens 4. Thelight scattering element 2 and the laser 1 are separated such that light being outputted from the light scattering element may be scattered and emitted backwards towards the laser 1. - Reflecting
elements 17 are arranged to direct backscattered light in the forward direction thus increasing the amount of light in the forward direction. - When arranging the light scattering element in a heat sink having a narrow through hole typically most of the backscattered light is shielded by the heat sink. If further limitation of light in the backwards direction is desired for the specific lighting application, such as in case of a spot light where only high brightness is desired and the blue speckle effect is not required, additional shielding 18 can optionally be provided, as illustrated in FIG.
- 4 b). The shielding can be arranged to shield off light outputted from the lighting device in any desirable direction limiting the distribution of light from the lamp depending on the specific application.
- The
light scattering element 2 is a Lumiramic YAG:Ce. The concentration of the active dopant (Ce in the case of YAG:Ce), the degree of scattering which is determined by the sintering conditions, and the thickness of the Lumiramic tile is utilized to control the degree of scattered light, converted light, and transmitted light being outputted from the lamp. As previously described part of the blue laser beam is transmitted through thelight scattering element 2. A high degree of transmitted coherent light is achievable with a low scattering degree, a low dopant degree, and/or a low thickness of the light scattering element, or a combination of the three. - The
light scattering element 2 may be arranged having a high degree of scattering which results in less transmitted coherent light and a more homogenous yellow, or white appearance of the light also in the forward directions. The lower degree of transmitted coherent light is an effect of high scattering degree, a high dopant concentration, and/or a high thickness, or a combination of the three. -
FIGS. 5 a-5 d are schematic cross-sectional side views of different shapes of the light scattering element in embodiments of a lighting device according to the present inventive concept. These shapes provide a secondary point of entrance for the backscattered light beam. - Part of the coherent light beam is absorbed in the Lumiramic tile, while part of the coherent light beam passes the Lumiramic tile. Further, a part of the coherent light beam is reflected by the Lumiramic tile back to where it came from, only over a 180′angle (back scattering). The back scattered coherent light can be used again to enforce the luminescent light spot (sparkle spot). Using a U-shape cube (
FIG. 5 c) firstly light is focused on the top Lumiramic tile where primarily the coherent light beam is absorbed by the Lumiramic tile. The back scattered coherent light meets the vertical walls of the U-shape cube, where the coherent light beam can make a second entry of a Lumiramic tile to convert into the desired wavelength. In this case the conversion efficiency of the blue coherent laser light in thelight scattering element 2 is improved. Other shapes with the same purpose are applicable (FIG. 5 b andFIG. 5 d). The tubular/cylindrical shape (FIG. 5 d) can provide a more filament like shape known from an incandescent lamp. The tubular shape creates more design freedom. - Further, the geometry of the light scattering element, which has been exemplified above, with reference to
FIGS. 5 a-5 d, can be chosen to select the luminance (cd/m2) visible to the eye, and the preferably to avoid a too high luminance, which is perceived as “glare” rather than sparkle, the latter which is one of the objects to achieve with the present inventive concept. The sparkle lighting effect desirable for use in lighting devices or candle lamps in applications like chandeliers. The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims.
Claims (15)
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP10160192 | 2010-04-16 | ||
EP10160192 | 2010-04-16 | ||
EP10160192.0 | 2010-04-16 | ||
PCT/IB2011/051539 WO2011128826A1 (en) | 2010-04-16 | 2011-04-11 | Lighting device |
Publications (2)
Publication Number | Publication Date |
---|---|
US20130128492A1 true US20130128492A1 (en) | 2013-05-23 |
US9194558B2 US9194558B2 (en) | 2015-11-24 |
Family
ID=44454109
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/640,757 Active 2031-10-27 US9194558B2 (en) | 2010-04-16 | 2011-04-11 | Lighting device having laser-excited luminescent material |
Country Status (6)
Country | Link |
---|---|
US (1) | US9194558B2 (en) |
EP (1) | EP2559077B1 (en) |
JP (1) | JP6087809B2 (en) |
CN (1) | CN102844895B (en) |
TW (1) | TW201144661A (en) |
WO (1) | WO2011128826A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20170074466A1 (en) * | 2015-09-16 | 2017-03-16 | Parhelion Incorporated | System and method of generating perceived white light |
WO2021013520A1 (en) | 2019-07-23 | 2021-01-28 | Signify Holding B.V. | Laser based white light source with adjustable sparkling |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102012204791A1 (en) * | 2012-03-26 | 2013-09-26 | Osram Gmbh | LIGHTING DEVICE WITH FLUORESCENT BODY ON COOLING BODY |
JP2013254889A (en) * | 2012-06-08 | 2013-12-19 | Idec Corp | Light-source apparatus and lighting apparatus |
JP6112782B2 (en) * | 2012-06-08 | 2017-04-12 | Idec株式会社 | Lighting device |
CN103115266B (en) | 2013-02-01 | 2014-03-12 | 深圳市保千里电子有限公司 | Laser lighting device |
CN104141923A (en) * | 2013-05-09 | 2014-11-12 | 陶晓培 | Converter for converting laser device into lighting device |
JP5949872B2 (en) * | 2014-10-27 | 2016-07-13 | ウシオ電機株式会社 | Fluorescent light source device |
CN110906281A (en) * | 2019-12-02 | 2020-03-24 | 江苏师范大学 | Transmission-type laser lighting device based on rod-shaped fluorescent material |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5535230A (en) * | 1994-04-06 | 1996-07-09 | Shogo Tzuzuki | Illuminating light source device using semiconductor laser element |
US7361938B2 (en) * | 2004-06-03 | 2008-04-22 | Philips Lumileds Lighting Company Llc | Luminescent ceramic for a light emitting device |
US8186864B2 (en) * | 2009-01-07 | 2012-05-29 | Olympus Corporation | Light source device |
Family Cites Families (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6350041B1 (en) | 1999-12-03 | 2002-02-26 | Cree Lighting Company | High output radial dispersing lamp using a solid state light source |
US6653765B1 (en) * | 2000-04-17 | 2003-11-25 | General Electric Company | Uniform angular light distribution from LEDs |
WO2003077389A1 (en) * | 2002-03-08 | 2003-09-18 | Sharp Kabushiki Kaisha | Light source apparatus and optical communication module comprising it |
AU2003238234A1 (en) * | 2002-06-13 | 2003-12-31 | Cree, Inc. | Semiconductor emitter comprising a saturated phosphor |
JP2006032885A (en) * | 2003-11-18 | 2006-02-02 | Sharp Corp | Light source device and optical transmission apparatus using it |
US7819549B2 (en) * | 2004-05-05 | 2010-10-26 | Rensselaer Polytechnic Institute | High efficiency light source using solid-state emitter and down-conversion material |
WO2006118104A1 (en) | 2005-04-26 | 2006-11-09 | Kabushiki Kaisha Toshiba | White led, and backlight and liquid crystal display device using the same |
EP3540794B1 (en) | 2006-03-10 | 2022-03-30 | Nichia Corporation | Light-emitting device |
CN101467091A (en) * | 2006-06-12 | 2009-06-24 | 皇家飞利浦电子股份有限公司 | A method and a lighting system |
US7703942B2 (en) | 2006-08-31 | 2010-04-27 | Rensselaer Polytechnic Institute | High-efficient light engines using light emitting diodes |
WO2008056292A1 (en) | 2006-11-07 | 2008-05-15 | Philips Intellectual Property & Standards Gmbh | Arrangement for emitting mixed light |
JP2008235439A (en) | 2007-03-19 | 2008-10-02 | Nec Lighting Ltd | White light source device |
US20090026913A1 (en) | 2007-07-26 | 2009-01-29 | Matthew Steven Mrakovich | Dynamic color or white light phosphor converted LED illumination system |
JP5071037B2 (en) | 2007-10-22 | 2012-11-14 | 日亜化学工業株式会社 | Semiconductor laser device |
TW200925248A (en) | 2007-12-12 | 2009-06-16 | wei-hong Luo | High brightness yellow-orange phosphor powder for using in warm white light emitting semiconductor |
US20090176430A1 (en) | 2008-01-07 | 2009-07-09 | Wang Wadelee | Method of making white light source by violet-LED |
WO2009112961A1 (en) | 2008-03-10 | 2009-09-17 | Koninklijke Philips Electronics N.V. | Laser light source and luminaire |
JP2009260053A (en) | 2008-04-17 | 2009-11-05 | Nichia Corp | Light emitting device |
JP2010015978A (en) * | 2008-06-05 | 2010-01-21 | Panasonic Corp | Under-water lighting apparatus |
EP2335295B1 (en) * | 2008-09-25 | 2021-01-20 | Lumileds LLC | Coated light emitting device and method of coating thereof |
-
2011
- 2011-04-11 JP JP2013504373A patent/JP6087809B2/en active Active
- 2011-04-11 CN CN201180019270.1A patent/CN102844895B/en active Active
- 2011-04-11 WO PCT/IB2011/051539 patent/WO2011128826A1/en active Application Filing
- 2011-04-11 EP EP11731088.8A patent/EP2559077B1/en active Active
- 2011-04-11 US US13/640,757 patent/US9194558B2/en active Active
- 2011-04-13 TW TW100112840A patent/TW201144661A/en unknown
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5535230A (en) * | 1994-04-06 | 1996-07-09 | Shogo Tzuzuki | Illuminating light source device using semiconductor laser element |
US7361938B2 (en) * | 2004-06-03 | 2008-04-22 | Philips Lumileds Lighting Company Llc | Luminescent ceramic for a light emitting device |
US8186864B2 (en) * | 2009-01-07 | 2012-05-29 | Olympus Corporation | Light source device |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20170074466A1 (en) * | 2015-09-16 | 2017-03-16 | Parhelion Incorporated | System and method of generating perceived white light |
US10047929B2 (en) * | 2015-09-16 | 2018-08-14 | James Redpath | System and method of generating perceived white light |
WO2021013520A1 (en) | 2019-07-23 | 2021-01-28 | Signify Holding B.V. | Laser based white light source with adjustable sparkling |
US11761606B2 (en) | 2019-07-23 | 2023-09-19 | Signify Holding B.V. | Laser based white light source with adjustable sparkling |
Also Published As
Publication number | Publication date |
---|---|
WO2011128826A1 (en) | 2011-10-20 |
JP6087809B2 (en) | 2017-03-01 |
US9194558B2 (en) | 2015-11-24 |
CN102844895B (en) | 2016-03-02 |
EP2559077A1 (en) | 2013-02-20 |
CN102844895A (en) | 2012-12-26 |
EP2559077B1 (en) | 2019-06-12 |
JP2013526019A (en) | 2013-06-20 |
TW201144661A (en) | 2011-12-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9194558B2 (en) | Lighting device having laser-excited luminescent material | |
US10527258B2 (en) | Scattered-photon extraction-based light fixtures | |
EP2803898B1 (en) | A light-emitting apparatus | |
JP5678128B2 (en) | Illumination system using multicolor light source and scattering element | |
KR101214135B1 (en) | Light Engine | |
JP5266605B2 (en) | Vehicle lighting | |
KR101758188B1 (en) | Solid state light source light bulb | |
EP2766936B1 (en) | Light emitting device with photoluminescence wavelength conversion component | |
US8614539B2 (en) | Wavelength conversion component with scattering particles | |
US20120140436A1 (en) | Solid-state lamps with light guide and photoluminescence material | |
US20120087103A1 (en) | Wavelength conversion component with a diffusing layer | |
US10066793B2 (en) | LED luminaire | |
JP2007294379A (en) | Lighting system |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: KONINKLIJKE PHILIPS ELECTRONICS N V, NETHERLANDS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:DRENTEN, RONALD REINDERT;VAN DER LUBBE, MARCELLUS JACOBUS JOHANNES;SIGNING DATES FROM 20120918 TO 20121119;REEL/FRAME:029420/0103 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
AS | Assignment |
Owner name: PHILIPS LIGHTING HOLDING B.V., NETHERLANDS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:KONINKLIJKE PHILIPS N.V.;REEL/FRAME:040060/0009 Effective date: 20160607 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 4 |
|
AS | Assignment |
Owner name: SIGNIFY HOLDING B.V., NETHERLANDS Free format text: CHANGE OF NAME;ASSIGNOR:PHILIPS LIGHTING HOLDING B.V.;REEL/FRAME:050837/0576 Effective date: 20190201 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1552); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 8 |